Oral Care Compositions

ABSTRACT

Described herein are oral care compositions comprising a crosslinked polyvinylpyrrolidone complexed with hydrogen peroxide, together with particular co-polymers as additional excipients; including some embodiments which further comprise a calcium abrasive.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Pat. Application No.14/868,469, filed Sep. 29, 2015, now allowed, which is a continuationU.S. Pat. Application No. 13/997,430, filed Jun. 24, 2013, now U.S. Pat.No. 9,174,070, which is a national stage entry under 35 U.S.C. § 371 ofInternational Patent Application No. PCT/US2011/038874, filed Jun. 2,2011, which is a continuation-in-part of International PatentApplication No. PCT/US2010/061711, filed Dec. 22, 2010, the contents ofwhich are hereby incorporated by reference in their entirety.

BACKGROUND

Dentifrice formulations comprising peroxide are known and useful forcleaning and whitening teeth. The peroxide can bleach the teeth, removestains, and kill cariogenic bacteria. However, peroxide compounds arehighly reactive, and consequently difficult to formulate. Moreover,hydrogen peroxide can spontaneously decompose to form oxygen gas (O₂)and water, so that on storage, the dentifrice containers may bloat,burst or leak, and the remaining formulation will not have enoughperoxide remaining to clean and whiten teeth effectively. Some initiallycomprise very high levels of peroxide, which decomposes over time, sothat the exact amount of peroxide delivered on application is variableand largely depends on how long and under what conditions the dentifricehas been stored.

Abrasives comprising calcium phosphate salts, such as calciumpyrophosphate, dicalcium orthophosphate dihydrate, tricalcium phosphate,and calcium polymetaphosphate are useful in dentifrice materials, as inaddition to providing an abrasive action which cleans the teeth, suchsalts provide a source of calcium and phosphate which can help build andrepair the teeth. Calcium salts such as calcium carbonate are alsocommonly used as abrasives. However, under oxidizing conditions, calciumions can readily form calcium peroxide (CaO₂) and calcium oxide (CaO,also known as quicklime), which is highly reactive and corrosive,reacting exothermically with water for example to form calcium hydroxide(Ca(OH)₂). Thus dentifrices using calcium salts are not preferred forformulation with peroxide.

Abrasive-free dentifrices comprising peroxide also present formulationchallenges. While the problem with interaction with the abrasive isremoved, the peroxide may still react with other components of theformulation and/or decompose to release O₂.

By exposure to aqueous environments, as in the oral cavity, the PVP-H₂O₂dissociates into individual species (PVP polymer and H₂O₂). The PVP-H₂O₂complex is generally comprised of about 80% by weight polyvinylpyrrolidone and 20% by weight H₂O₂. Single phase whitening dentifricecompounds comprising PVP-H₂O₂ complexes are described, e.g., inWO/2007/037961, and its parent US Pub. No. US 2007-0071695 A1, thecontents of which are incorporated herein by reference.

While there are numerous publications of gels comprising peroxide, suchgels are generally for use with dental trays or strips, rather than forapplication using a toothbrush, and such gels are not necessarilysuitable for use as a dentifrice because they may adhere to thetoothbrush, rather than rinsing off easily, and leave the consumer withan unpleasant experience due to the lack of foaming provided by theproduct.

There is thus a need for improved peroxide dentifrice formulations thatare stable for long-term storage and are suitable for everyday consumeruse.

SUMMARY

In some embodiments, the present invention provides oral carecompositions that are stable during long term storage and remaineffective to clean and whiten teeth. In some embodiments, the inventionprovides an oral care composition comprising: (i) a crosslinkedpolyvinylpyrrolidone complexed with hydrogen peroxide and (ii) anabrasive. In some embodiments, the abrasive is a calcium abrasive. Inother embodiments, the invention provides an oral care compositioncomprising a crosslinked polyvinylpyrrolidone complexed with hydrogenperoxide, and a stabilizing amount of additional linear and/orcrosslinked polyvinylpyrrolidone. In further embodiments, the inventionprovides an oral care composition comprising (i) a crosslinkedpolyvinylpyrrolidone complexed with hydrogen peroxide, and an ethyleneoxide, propylene oxide block co-polymer of formula (ethyleneoxide)_(x)-(propylene oxide)_(y) wherein x is an integer of 80-150 and yis an integer 30-80, having an average molecular weight of greater than5000 Da. Further embodiments of the invention will be apparent from thedetailed description and the examples.

DETAILED DESCRIPTION

As used throughout, ranges are used as shorthand for describing each andevery value that is within the range. Any value within the range can beselected as the terminus of the range.

All references cited herein are hereby incorporated by reference intheir entireties.

In the event of a conflict in a definition in the present disclosure andthat of a cited reference, the present disclosure controls.

As used herein, the phrase “unacceptable level of phase separation”refers to the extent of phase separation that: (1) occurs when a sampleis centrifuged at 2050 rpm in a LumiSizer 110 analytical centrifuge; and(2) is predictive of a product that possesses unacceptable physicalstability.

In some embodiments, the present invention provides oral carecompositions comprising a crosslinked polyvinylpyrrolidone complexedwith hydrogen peroxide, and a stabilizing amount of additional linearand/or crosslinked polyvinylpyrrolidone and/or with an ethylene oxide,propylene oxide block co-polymer of formula (ethyleneoxide)_(x-)(propylene oxide)_(y) wherein x is an integer of 80-150 and yis an integer 30-80, having an average molecular weight of greater than5000 Da. Some embodiments further comprise an abrasive. In someembodiments, the abrasive is a calcium abrasive.

Accordingly, the invention provides a dentifrice comprising (i) acrosslinked polyvinylpyrrolidone complexed with hydrogen peroxide and(ii) an ethylene oxide, propylene oxide block co-polymer of formula(ethylene oxide)_(x)-(propylene oxide)_(y) wherein x is an integer of80-150, e.g. 100-130, e.g. about 118, and y is an integer 30-80, e.g.about 60-70, e.g. about 66, having an average molecular weight ofgreater than 5000, e.g., 8000 - 13000 Da, e.g. about 9800. In someembodiments, the invention provides a toothpaste comprising an abrasive,e.g., a calcium abrasive. In other embodiments, the invention providesan abrasive-free gel.

In one embodiment, the invention provides a dentifrice comprising (i) acrosslinked polyvinylpyrrolidone complexed with hydrogen peroxide and(ii) a calcium abrasive, in a dentifrice carrier.

For example, the invention provides Composition 1, a toothpastecomprising (i) a whitening complex comprising crosslinkedpolyvinylpyrrolidone complexed with hydrogen peroxide, (ii) a calciumabrasive, e.g.,

-   1.1. Composition 1 wherein the whitening complex contains about    10-30%, e.g., 15-25%, for example about 17-22% of hydrogen peroxide    by weight, and about 5-15%, for example about 7-12% total nitrogen    by weight; for example, having substantially the same specifications    as Polyplasdone® XL-10, e.g., Polyplasdone® XL-10F, e.g., available    from International Specialty Products (Wayne, NJ);-   1.2. Composition 1 or 1.1 wherein the calcium abrasive comprises a    calcium phosphate salt, e.g., calcium pyrophosphate, dicalcium    orthophosphate dihydrate, tricalcium phosphate, and calcium    polymetaphosphate;-   1.3. Any of the foregoing compositions wherein the calcium abrasive    comprises calcium pyrophosphate;-   1.4. Any of the foregoing compositions wherein the calcium abrasive    comprises calcium carbonate;-   1.5. Any of the foregoing compositions wherein the total amount of    hydrogen peroxide by weight of the composition is 0.5-3%, e.g., 0.75    -1.5%, e.g. about 1%;-   1.6. Any of the foregoing compositions which contains less than 2%    water, e.g., less than 1% water, e.g., is substantially anhydrous;-   1.7. Any of the foregoing compositions comprising polymer thickeners    selected from (i) polyethylene glycol, (ii) polyethylene glycol -    polypropylene glycol block copolymers having a molecular weight of    at least 5000, and (iii) combinations thereof;-   1.8. The preceding composition comprising an ethylene oxide,    propylene oxide block co-polymer of formula (ethylene    oxide)_(x)-(propylene oxide)_(y) wherein x is an integer of 80-150,    e.g. 100-130, e.g. about 118, and y is an integer 30-80, e.g. about    60-70, e.g. about 66, having an average molecular weight of greater    than 5000, e.g., 8000 -13000 Da, e.g. about 9800;-   1.9. The preceding composition additionally comprising polyethylene    glycol of average molecular weight 400 to 800, e.g., about 600 Da;-   1.10. Any of the foregoing compositions additionally comprising    humectants, e.g. selected from glycerin, propylene glycol or a    combination thereof;-   1.11. Any of the foregoing compositions additionally comprising    atartar control agent, e.g., selected from tetrasodium pyrophosphate    (TSPP) and sodium tripolyphosphate (STPP);-   1.12. Any of the foregoing compositions additionally comprising a    surfactant, e.g., sodium lauryl sulfate (SLS);-   1.13. Any of the foregoing compositions additionally comprising an    antibacterial agent, e.g., triclosan;-   1.14. Any of the foregoing compositions additionally comprising an    antioxidant, e.g., butylated hydoxytoluene (BHT);-   1.15. Any of the foregoing compositions comprising any or all of the    following ingredient classes and/or particular ingredients by    weight:

Humectants 25-40%, e.g. Glycerin 3-7%, e.g., about 5% Propylene glycol20-30%, e.g., about 25% Thickeners, e.g. Fumed silica 0-2%, e.g., about1.5% Polymers 10-30%, e.g., Ethylene oxide, propylene oxide blockco-polymer, avg. MW >5 kDa 5-15%, e.g., about 10% Polyethylene glycol600 5-15%, e.g., about 10% Polyvinylpyrrolidone 0-10% Whitener, 3-10%,e.g., Crosslinked polyvinylpyrrolidone complexed with 15-25% hydrogenperoxide 3-10%, e.g., about 5.5% Abrasive, 25-45%, e.g. Calciumpyrophosphate 25-45%, e.g., about 35% Fluoride, 0 - 1%, e.g. Sodiummonofluorophosphate 0.5 - 1%, e.g., about 0.76% Surfactant, e.g., SLS0-3% Tartar control agent, e.g. TSPP 0.5-5%, e.g., about 2% Antioxidant,0.01-5%, e.g. BHT 0.03% Flavorings 0.1-5% Water <3%

-   1.16. The composition resulting from the combination of the    preceding ingredients.

In another embodiment, the invention provides a dentifrice comprising acrosslinked polyvinylpyrrolidone complexed with hydrogen peroxide,together with additional linear and/or crosslinked polyvinylpyrrolidone,and a dentifrice carrier.

For example, the invention provides Composition 2, a gel non-abrasivedentifrice comprising a crosslinked polyvinylpyrrolidone complexed withhydrogen peroxide, together with additional linear and/or crosslinkedpolyvinylpyrrolidone, e.g.,

-   2.1. Composition 1 wherein the whitening complex contains about    10-30%, e.g., 15-25%, for example about 17-22% of hydrogen peroxide    by weight, and about 5-15%, for example about 7-12% total nitrogen    by weight; for example, having substantially the same specifications    as Polyplasdone® XL-10, e.g., Polyplasdone@ XL-10F, e.g., available    from International Specialty Products (Wayne, NJ);-   2.2. Composition 2 or 2.1 wherein the total amount of hydrogen    peroxide by weight of the composition is 0.5-3%, e.g., 0.75 -1.5%,    e.g. about 1%;-   2.3. Any of the foregoing compositions which contains less than 3%    water, e.g., less than 1% water, e.g., is substantially anhydrous;-   2.4. Any of the foregoing compositions comprising polymer thickeners    selected from (i) polyethylene glycol, (ii) polyethylene glycol -    polypropylene glycol block copolymers having a molecular weight of    at least 5000, and (iii) combinations thereof;-   2.5. The preceding composition comprising an ethylene oxide,    propylene oxide block co-polymer of formula (ethylene    oxide)_(x)-(propylene oxide)_(y) wherein x is an integer of 80-150,    e.g. 100-130, e.g. about 118, and y is an integer 30-80, e.g. about    60-70, e.g. about 66, having an average molecular weight of greater    than 5000, e.g., 8000 -13000 Da, e.g. about 9800;-   2.6. The preceding composition additionally comprising polyethylene    glycol of average molecular weight 400 to 800, e.g., about 600 Da;-   2.7. Any of the foregoing compositions additionally comprising    humectants, e.g. selected from glycerin, propylene glycol or a    combination thereof;-   2.8. Any of the foregoing compositions additionally comprising    atartar control agent, e.g., selected from tetrasodium pyrophosphate    (TSPP) and sodium tripolyphosphate (STPP);-   2.9. Any of the foregoing compositions additionally comprising a    surfactant, e.g., sodium lauryl sulfate (SLS);-   2.10. Any of the foregoing compositions additionally comprising an    antibacterial agent, e.g., triclosan;-   2.11. Any of the foregoing compositions additionally comprising an    antioxidant, e.g., butylated hydoxytoluene (BHT);-   2.12. Any of the foregoing compositions comprising any or all of the    following ingredient classes and/or particular ingredients by    weight:

Humectants 50-70%, e.g. Glycerin 40-55%, e.g. about 47% Propylene glycol10-20%, e.g., about 15% Fumed silica 0-2% Polymers 10-40%, e.g.,Ethylene oxide, propylene oxide block co-polymer, avg. MW >5 kDa 1-15%,e.g., about 5% Polyethylene glycol 600 5-15%, e.g., about 10%Polyvinylpyrrolidone 1-20%, e.g., about 10% Whitener, 3-10%, e.g.,Crosslinked polyvinylpyrrolidone complexed with 15-25% hydrogen peroxide3-10%, e.g., about 5.5% Fluoride, 0 - 1%, e.g. Sodiummonofluorophosphate 0.5 - 1%, e.g., about 0.76% Surfactant, 0-5%, e.g.SLS 1-3%, e.g., about 2% Tartar control agent, e.g. TSPP 0.5-5%, e.g.,about 2% Antioxidant, 0.01-5%, e.g. BHT 0.03% Flavorings 0.1-5% Water<3%

-   2.13. The composition resulting from the combination of the    preceding ingredients.

In some embodiments, the present invention provides oral carecompositions comprising: a crosslinked polyvinylpyrrolidone complexedwith hydrogen peroxide, a stabilizing amount of an additional linearand/or crosslinked polyvinylpyrrolidone, an abrasive and a humectant.

Some embodiments provide oral care compositions comprising: from about0.5 to about 16.5%, by weight, crosslinked polyvinylpyrrolidonecomplexed with hydrogen peroxide. Other embodiments provide oral carecompositions comprising: from about 1to about 15%, by weight,crosslinked polyvinylpyrrolidone complexed with hydrogen peroxide. Stillother embodiments provide oral care compositions comprising: from about3 to about 12%, by weight, crosslinked polyvinylpyrrolidone complexedwith hydrogen peroxide. Yet other embodiments provide oral carecompositions comprising: from about 4 to about 10%, by weight,crosslinked polyvinylpyrrolidone complexed with hydrogen peroxide. Whileother embodiments provide oral care compositions comprising: from about5 to about 8%, by weight, crosslinked polyvinylpyrrolidone complexedwith hydrogen peroxide. In some embodiments, the oral care compositionscomprise 5.5%, by weight, crosslinked polyvinylpyrrolidone complexedwith hydrogen peroxide.

In some embodiments, the present invention provides oral carecompositions comprising from about 1 to about 20% of an additionallinear and/or crosslinked polyvinylpyrrolidone. Some embodiments providecompositions comprising from about 1 to about 15%, by weight, of anadditional linear and/or crosslinked polyvinylpyrrolidone. Someembodiments provide compositions comprising from about 5 to about 15%,by weight, of an additional linear and/or crosslinkedpolyvinylpyrrolidone. Other embodiments provide compositions comprisingfrom about 7 to about 12%, by weight, of an additional linear and/orcrosslinked polyvinylpyrrolidone. Further embodiments provide oral carecompositions comprising from about 8 to about 11%, by weight, of anadditional linear and/or crosslinked polyvinylpyrrolidone. Still furtherembodiments provide compositions comprising from about 8.5 to about 10%,by weight, of an additional linear and/or crosslinkedpolyvinylpyrrolidone. Still other embodiments provide oral carecompositions comprising 9.9% or 10%, by weight, of an additional linearand/or crosslinked polyvinylpyrrolidone. Yet other embodiments provideoral care compositions comprising about 9%, by weight, of an additionallinear and/or crosslinked polyvinylpyrrolidone.

Some embodiments of the present invention provide gel-based peroxidecompositions further comprise a calcium abrasive. In some embodiments,the compositions comprise from about 9 to about 25%, by weight,propylene glycol. In some embodiments, the compositions comprise fromabout 14 to about 32%, by weight, glycerin. In other embodiments, thecompositions comprise less than 20%, by weight, of a calcium abrasive.Some embodiments provide compositions comprising from about 9 to about25%, by weight, propylene glycol; from about 14 to about 32%, by weight,glycerin; and less than 20%, by weight, of a calcium abrasive.

Still other embodiments provide oral care compositions comprising fromabout 20 to about 60%, by weight, humectant.

Yet further embodiments provide oral care compositions comprising fromabout 5 to about 15%, by weight, abrasive.

The compositions of the invention a “low water” content, meaning that atotal concentration of water, including any free water and all watercontained in any ingredients, is less than about 5%, preferably lessthan 3%, preferably less than 2% water.

Where abrasives are present, the average particle size is generallyabout 0.1 to about 30 microns, for example about 1 to about 20 or about5 to about 15 microns.

In various embodiments of the present invention, the oral compositioncomprises an anticalculus (tartar control) agent. Generally, tartarcontrol agents are categorized as being incompatible with some whiteningagents, but embodiments of the present invention incorporate tartarcontrol agents and whitening agents in a single phase whiteningcomposition. Suitable anticalculus agents include without limitationphosphates and polyphosphates (for example pyrophosphates),polyaminopropanesulfonic acid (AMPS), hexametaphosphate salts, zinccitrate trihydrate, polypeptides, polyolefin sulfonates, polyolefinphosphates, diphosphonates. The anticalculus agent is present at about0.1% to about 30%. The oral composition may include a mixture ofdifferent anticalculus agents. In one preferred embodiment, tetrasodiumpyrophosphate (TSPP) and sodium tripolyphosphate (STPP) are used. Theanticalculus agent comprises TSPP at about 1-2% and STPP at about 7% toabout 10%.

The oral care composition can optionally include at least one orallyacceptable source of fluoride ions. Any known or to be developed in theart may be used. Suitable sources of fluoride ions include fluoride,monofluorophosphate and fluorosilicate salts. One or more fluorideion-releasing compound is optionally present in an amount providing atotal of about 100 to about 20,000 ppm, about 200 to about 5,000 ppm, orabout 500 to about 2,500 ppm, fluoride ions.

The compositions of the invention may also comprise various dentifriceingredients to adjust the rheology and feel of the composition such ashumectants, surface active agents, thickening or gelling agents, etc.

The compositions of the present invention may comprise a surface activeagent (surfactant). Suitable surfactants include without limitationwater-soluble salts of C₈₋₂₀ alkyl sulfates, sulfonated monoglyceridesof C₈₋₂₀ fatty acids, sarcosinates, taurates, sodium lauryl sulfate,sodium cocoyl monoglyceride sulfonate, sodium lauryl sarcosinate, sodiumlauryl isoethionate, sodium laureth carboxylate and sodium dodecylbenzene sulfonate, and cocoamidopropyl betaine.

The compositions of the present invention optionally comprise athickener. Any orally acceptable thickening agent can be used, includingwithout limitation carbomers, also known as carboxyvinyl polymers,carrageenans, also known as Irish moss and more particularly-carrageenan (iota-carrageenan), high molecular weight polyethyleneglycols (such as CARBOWAX®, available from The Dow Chemical Company),cellulosic polymers such as hydroxyethylcellulose,carboxymethylcellulose (CMC) and salts thereof, e.g., CMC sodium,natural gums such as karaya, xanthan, gum arabic and tragacanth,colloidal magnesium aluminum silicate, and colloidal and/or fumed silicaand mixtures of the same. One or more thickening agents are optionallypresent in a total amount of about 0.1% to about 90%, for example about1% to about 50% or about 5% to about 35%.

In various preferred embodiments, the carrier may comprise polymersand/or copolymers of polyethylene glycol, of ethylene oxide / propyleneoxide, and of silicone. If such copolymers/polymers are used, they maybe selected from commercially available materials. Block copolymers ofethylene oxide / propylene oxide are useful, but higher molecularweight, e.g., > 5000 Da are preferred, e.g. including PLURACARE® L1220(available from BASF, Wyandotte, Mich., United States of America). Lowor medium molecular weight polyethylene glycol, e.g., PEG 400, PEG 600,PEG 800, PEG 1000 and mixtures thereof are also useful. It is preferredthat the carrier(s) provide a dentifrice with a viscosity of about10,000 CPS to about 700,000 CPS, preferably about 30,000 CPS to about300,000 CPS.

As recognized by one of skill in the art, the oral compositions of thepresent invention optionally include other materials, such as forexample, anti-caries agents, desensitizing agents, viscosity modifiers,diluents, surface active agents, such as surfactants, emulsifiers, andfoam modulators, pH modifying agents, abrasives, in addition to thoselisted above, humectants, mouth feel agents, sweetening agents, flavoragents, colorants, preservatives, and combinations thereof. It isunderstood that while general attributes of each of the above categoriesof materials may differ, there may be some common attributes and anygiven material may serve multiple purposes within two or more of suchcategories of materials. Preferably, the carrier is selected forcompatibility with other ingredients of the composition.

Flavorants, sweeteners, colorants, foam modulators, mouth-feel agentsand others additively may be included if desired, in the composition.

The compositions of the present invention optionally comprise one ormore further active material(s), which is operable for the prevention ortreatment of a condition or disorder of hard or soft tissue of the oralcavity, the prevention or treatment of a physiological disorder orcondition, or to provide a cosmetic benefit.

The compositions may include a stannous ion or a stannous ion source.Suitable stannous ion sources include without limitation stannousfluoride, other stannous halides such as stannous chloride dihydrate,stannous pyrophosphate, organic stannous carboxylate salts such asstannous formate, acetate, gluconate, lactate, tartrate, oxalate,malonate and citrate, stannous ethylene glyoxide and the like. One ormore stannous ion sources are optionally and illustratively present in atotal amount of about 0.01% to about 10%, for example about 0.1% toabout 7% or about 1% to about 5%.

The compositions of the present invention optionally comprise anantimicrobial (e.g., antibacterial) agent. A further illustrative listof useful antibacterial agents is provided in such as those listed inU.S. Pat. No. 5,776,435 to Gaffar et al., the contents of which areincorporated herein by reference. One or more antimicrobial agents areoptionally present in an antimicrobial effective total amount, typicallyabout 0.05% to about 10%, for example about 0.1% to about 3%.

The compositions of the present invention optionally comprise anantioxidant. Any orally acceptable antioxidant can be used, includingbutylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), vitaminA, carotenoids, vitamin E, flavonoids, polyphenols, ascorbic acid,herbal antioxidants, chlorophyll, melatonin, and mixtures thereof.

The compositions of the present invention optionally comprise asialagogue or saliva-stimulating agent, an antiplaque agent, ananti-inflammatory agent, and/or a desensitizing agent.

While ingredients are sometimes identified herein by category, e.g.,humectant, antioxidant, thickener, etc., this identification is forconvenience and clarity, but is not intended to be limiting. All of theingredients in the compositions may have functions in addition to theirprimary function, and may contribute to the overall properties of thecomposition, including its stability, efficacy, consistency, mouthfeel,taste, odor and so forth.

Methods are provided to whiten an oral surface in a human or animalsubject comprising storing in stable form a composition of theinvention, e.g., Composition 1, et seq. or Composition 2, et seq. asdescribed above, and contacting said composition with the oral surface.As used herein “animal subject” includes higher order non-human mammalssuch as canines, felines, and horses. The oral care composition iscontacted with an oral surface of the mammalian subject to therebywhiten teeth in a highly efficacious manner, without any negativeinteraction between the whitening agent, the peroxide incompatibleabrasive, and other ingredients.

In various embodiments, it is preferred that the oral care compositionis applied and contacted with the oral surface. The dentifrice, preparedin accordance with the present invention is preferably applied regularlyto an oral surface, preferably on a daily basis, at least one time dailyfor multiple days, but alternately every second or third day. Preferablythe oral composition is applied to the oral surfaces from 1 to 3 timesdaily, for at least 2 weeks up to 8 weeks, from four months to threeyears, or more up to lifetime.

In some embodiments, the diameter of the top of the tube in which the acomposition of the present invention is packaged, expands less than 0.1cm, after 1 week of aging at 60° C. In some embodiments, the diameter ofthe top of the tube in an oral care composition of the present inventionis packaged, expands less than 0.05 cm, after 1 week of aging at 60° C.In other embodiments, the diameter of the top of the tube in which acomposition of the present invention is packaged, expands less than 0.04cm, after 1 week of aging at 60° C. In further embodiments, the diameterof the top of the tube in which a composition of the present inventionis packaged, expands less than 0.03 cm, after 1 week of aging at 60° C.In other embodiments, the diameter of the top of the tube in which acomposition of the present invention is packaged, expands less than 0.02cm, after 1 week of aging at 60° C. In yet other embodiments, thediameter of the top of the tube in which a composition of the presentinvention is packaged, expands less than 0.01 cm, after 1 week of agingat 60° C. While in other embodiments, the diameter of the top of thetube in which a composition of the present invention is packaged, doesnot expand to a measurable extent.

In some embodiments, the compositions of the present invention do notexhibit an unacceptable level of phase separation after 30 minutes at2050 rpm in a LumiSizer 110 analytical centrifuge. In other embodiments,the compositions of the present invention do not exhibit an unacceptablelevel of phase separation after 35 minutes at 2050 rpm in a LumiSizer110 analytical centrifuge. In further embodiments, the compositions ofthe present invention do not exhibit an unacceptable level of phaseseparation after 40 minutes at 2050 rpm in a LumiSizer 110 analyticalcentrifuge. In still further embodiments, the compositions of thepresent invention do not exhibit an unacceptable level of phaseseparation after 45 minutes at 2050 rpm in a LumiSizer 110 analyticalcentrifuge. In yet other embodiments, the compositions of the presentinvention do not exhibit an unacceptable level of phase separation after50 minutes at 2050 rpm in a LumiSizer 110 analytical centrifuge. In someembodiments, the compositions of the present invention do not exhibit anunacceptable level of phase separation after 55 minutes at 2050 rpm in aLumiSizer 110 analytical centrifuge. Still other embodiments providecompositions that do not exhibit an unacceptable level of phaseseparation after 60 minutes at 2050 rpm in a LumiSizer 110 analyticalcentrifuge. While other embodiments provide compositions that do notexhibit an unacceptable level of phase separation after 65 minutes at2050 rpm in a LumiSizer 110 analytical centrifuge. In some embodiments,the compositions of the present invention do not exhibit an unacceptablelevel of phase separation after 70 minutes at 2050 rpm in a LumiSizer110 analytical centrifuge. In some embodiments, the compositions of thepresent invention do not exhibit an unacceptable level of phaseseparation after 75 minutes at 2050 rpm in a LumiSizer 110 analyticalcentrifuge. In some embodiments, the compositions of the presentinvention do not exhibit an unacceptable level of phase separation after80 minutes at 2050 rpm in a LumiSizer 110 analytical centrifuge. In someembodiments, the compositions of the present invention do not exhibit anunacceptable level of phase separation after 85 minutes at 2050 rpm in aLumiSizer 110 analytical centrifuge. In some embodiments, thecompositions of the present invention do not exhibit an unacceptablelevel of phase separation after 90 minutes at 2050 rpm in a LumiSizer110 analytical centrifuge. In some embodiments, the compositions of thepresent invention do not exhibit an unacceptable level of phaseseparation after 95 minutes at 2050 rpm in a LumiSizer 110 analyticalcentrifuge. In some embodiments, the compositions of the presentinvention do not exhibit an unacceptable level of phase separation after100 minutes at 2050 rpm in a LumiSizer 110 analytical centrifuge. Insome embodiments, the compositions of the present invention do notexhibit an unacceptable level of phase separation after 105 minutes at2050 rpm in a LumiSizer 110 analytical centrifuge. In some embodiments,the compositions of the present invention do not exhibit an unacceptablelevel of phase separation after 110 minutes at 2050 rpm in a LumiSizer110 analytical centrifuge. In some embodiments, the compositions of thepresent invention do not exhibit an unacceptable level of phaseseparation after 115 minutes at 2050 rpm in a LumiSizer 110 analyticalcentrifuge. In some embodiments, the compositions of the presentinvention do not exhibit an unacceptable level of phase separation after120 minutes at 2050 rpm in a LumiSizer 110 analytical centrifuge. Insome embodiments, the compositions of the present invention do notexhibit an unacceptable level of phase separation after 125 minutes at2050 rpm in a LumiSizer 110 analytical centrifuge.

In some embodiments, the diameter of the top of the tube in which acomposition of the present invention is packaged, expands less than0.01% of the top diameter of the tube, after 1 week of aging at 60° C.In some embodiments, the diameter of the top of the tube in which acomposition of the present invention is packaged, expands less than0.05% of the top diameter of the tube, after 1 week of aging at 60° C.In some embodiments, the diameter of the top of the tube in which acomposition of the present invention is packaged, expands less than 0.1%of the top diameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 0.5% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 1% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 3% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 5% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 10% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 15% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 20% of the topdiameter of the tube, after 1 week of aging at 60° C.

In some embodiments, the diameter of the top of the tube in which acomposition of the present invention is packaged, expands less than 25%of the top diameter of the tube, after 1 week of aging at 60° C. Inother embodiments, the diameter of the top of the tube in which acomposition of the present invention is packaged, expands less than 30%of the top diameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 35% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 40% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 45% of the topdiameter of the tube, after 1 week of aging at 60° C. In someembodiments, the diameter of the top of the tube in which a compositionof the present invention is packaged, expands less than 50% of the topdiameter of the tube, after 1 week of aging at 60° C.

The invention is illustrated in the following non-limiting examples.

EXAMPLES Example 1

A gel dentifrice having a peroxide composition of about 1% is preparedhaving the following ingredients:

TABLE 1 Ingredient % (w/w) 85% syrupy phosphoric acid 0.2 PEG₁₁₈/PPG₆₆co-polymer 5 Glycerin 47 Propylene glycol 15 PEG 600 10 PVP 10Crosslinked PVP / H₂O₂ 5.5 TSPP 2 Sucralose 0.05 Sodium saccharine 0.6Sodium monofluorophosphate 0.76 Sodium lauryl sulfate 2 BHT 0.03 Mintflavor 2

Example 2

A gel dentifrice having a peroxide composition of about 1% is preparedhaving the following ingredients:

TABLE 2 Ingredient % (w/w) 85% syrupy phosphoric acid 0.2 Glycerin 25.36PEG₁₁₈/PPG₆₆ co-polymer 7.5 PEG 600 10 Propylene glycol 25 CrosslinkedPVP / H₂O₂ 5.5 TSPP 2 Sucralose 0.05 Sodium saccharin 0.6 Sodiummonofluorophosphate 0.76 Calcium pyrophosphate 10 PVP 9 BHT 0.03 Flavor2 Sucralose 0.05 Sodium lauryl sulfate 2

Example 3

A toothpaste having a peroxide content of about 1% is prepared with thefollowing ingredients:

TABLE 3 Ingredient % (w/w) 85% syrupy phosphoric acid 0.2 PEG₁₁₈/PPG₆₆co-polymer 10 Glycerin 5 PEG 600 10 Propylene glycol 25 Crosslinked PVP/ H₂O₂ 5.5 TSPP 2 Sucralose 0.05 Sodium saccharine 0.6 Sodiummonofluorophosphate 0.76 Calcium pyrophosphate 35 Fumed silica 1.5 BHT0.03 Mint flavor 2.25

Example 4

The in vitro whitening efficacy of the compositions of Examples 1 and 3are tested versus commercial whitening dentifrices.

Brushing test: The in vitro whitening efficacy of the products is testedby brushing experiments. Bovine teeth are prophy stained to achievesimilar initial lightness values. The bovine teeth are mounted in a trayfor brushing study. A 1:1 slurry of dentifrice to deionized water isprepared and 25 grams added to brushing tray. The stained bovine teethare brushed for for 20 minutes at 120 strokes/min. This is intended toapproximate one week of bushing (1.5 min brushing, twice a day for sevendays = 21 minutes/week). Teeth are rinsed with 100 g deionized water,then the color (L*a*b* values) is measured with a spectrophotometer.This is repeated three times.

The spectrophotometer used is Spectroshade from MHT. The measurementscale is the CIE L*a*b* (CIELAB) scale developed by the InternationalCommission on Illumination (CIE). CIELAB is an opponent color systembased on the fact that retinal color stimuli are translated intodistinctions between light and dark, red and green, and blue and yellow.CIELAB indicates these values with three axes: L*, a*, and b*. The Lvalue indicates the lightness of a color, where L=0 is black and L=100is white. ΔL = L_(brushed) - L_(initial). Thus, a larger positive ΔLvalue = whiter teeth. The a value ranges between +a = magenta and -a =green. The b value ranges between +b = yellow and -b = blue. The W valueincorporates the L, a and b values to describe how close the measuredcolor is to true white, where W* = (a2 + b2 + (L*-100)2)½. A largernegative ΔW value corresponds to greater whitening.

In comparing the toothpaste formulation of Example 3 with a leadingcommercial whitening toothpaste (Brand A), the formulation of Example 3shows significantly greater whitening:

TABLE 4 ΔL using Brand A and Example 3: 20 mins 40 mins 60 mins 80 minsBrand A 2.1 + 0.6 3.1 + 0.7 3.6 + 0.6 3.8 + 1.0 Example 3 4.4 + 0.95.4 + 0.9 6.5 + 1.0 7.5 + 0.9

TABLE 5 ΔW using Brand A and Example 3: 20 mins 40 mins 60 mins 80 minsBrand A -2.2 + 0.5 -3.1 + 0.6 -3.5 + 0.4 -3.6 + 0.9 Example 3 -4.0 + 0.9-4.8 + 1.4 -6.1 + 1.6 -7.0+ 1.3

Similar results are obtained with the gel of Example 1. After fourcycles of brushing (80 minutes), the ΔL and ΔW are as follows:

TABLE 6 ΔL and ΔW using Brand A and Example 1 ΔL ΔW Brand A 3.8 + 1.0-3.6 + 0.9 Example 1 7.3 + 2.6 -6.0 + 2.8

Bleaching test: Hard abrasive particles serve to break up the stainduring the act of brushing when they are rubbed against the stain by thebristles of the toothbrush. Peroxide whitens both extrinsic (surfacestains) and intrinsic stains (below the surface of enamel) through achemical reaction in which the unsaturated bonds in colored stainmolecules are oxidized by peroxide to become colorless. In this testmethod stained hydroxyapatite disks are soaked in dentifrice slurry. Asdisks are soaked, rather than brushed, stains will be bleached bytoothpaste containing peroxide but should not be removed by toothpastescontaining only abrasives. The substrate used is 1” diameterhydroxyapatite (HAP) disks (human enamel is -96% hydroxyapatite byweight; human dentin is -70% hydroxyapatite by weight). The HAP arestained using a mixture of common foods that stain teeth: 1 part 1%instant coffee solution (Maxwell House), 1 part brewed black tea (LiptonBlack Tea soaked for 2 min in hot water), 1 part red wine (Cabernet).The HAP disks are soaked overnight in artificial saliva. The salivatreated disks are soaked in staining solution for 2 hrs, rinsed withwater, and dried. The disks are then soaked in a stirring dentifriceslurry for 2 min, rinsed with water and dried.

TABLE 7 ΔW using Brand A and Example 1 in bleaching test; stained HAPdisks soaked in 1:2 dentifrice to water slurry for 2 min L a b W* ΔWControl 80.17 5.51 6.18 21.49 Brand A 85.79 3.02 4.24 15.13 -6.36Example 1 95.43 0.07 1.61 4.85 -16.64

Example 1 is then further tested versus a commercially available 1%peroxide toothpaste (Brand B).

TABLE 8 ΔW for Example 1 versus Brand B in a bleaching test; stained HAPdisks soaked in a 1:1 dentifrice to water slurry for 2 minutes. L a b W*ΔW Control 79.59 5.52 6.43 22.10 Example 1 96.61 -0.31 1.37 3.67 -18.43Brand B 96.36 -0.91 3.45 5.10 -17.00

The data described in Table 8 indicates that an exemplary composition ofthe present invention provides a significant improvement in ΔW over acommercially available 1% peroxide toothpaste.

Example 5

The objective of the consumer test is to determine how the two testformulas with peroxide compare in consumer preference and whiteningperformance after 2 weeks of use vs. the leading peroxide andnonperoxide competition.

Two Week Results: Both Examples 1 and 3 deliver higher % of noticeablewhitening amongst consumers who perceived their teeth to be whiter vs.Brand A after 1 week of use [71% for Example 1 (1% gel), 77% for Example3 (1% paste), 58% for Brand A]. Also two statements come up higher forboth Examples than for Brand A: “This toothpaste gives me 360 degreecoverage for an all over white” and “This toothpaste is the mostconvenient way to get noticeably whiter teeth in just 1 week”. BothExamples were significantly better than Brand B in overall and tasteliking.

Example 6

The toothpaste of Example 3 is tested for stability versus acommercially available 1% peroxide toothpaste. Peroxide-containingcompositions which bloat to an unacceptable extent would not be expectedto provide the level of whitening suitable for a toothpaste composition.

Tube bloating: The diameter of the tube is measured at the bottom (closeto cap), the midpoint, and the top (close to crimp), before and after 1week of aging at 60° C. The elevated temperature accelerates the aging,approximating the degree of degradation that can be expected to occurover long-term storage at room temperature.

TABLE 9 Top Middle Bottom Set 1 (change in cm) Set 2 (change in cm) Set1 (change in cm) Set 2 (change in cm) Set 1 (change in cm) Set 2 (changein cm) Example 3 0.02 0.00 0.20 0.10 0.10 -0.20 Brand B 0.10 0.20 0.100.20 -0.10 0.20

Physical separation: Samples are centrifuged using an analyticalcentrifuge (LumiSizer 110 from L.U.M. GmbH, Berlin), which measuresseparation of the product by measuring optical transmission through thetube as a function of time.

The results show that it takes longer for Example 3 to separate thanBrand B:

TABLE 10 Sample Example 3 Brand B Time to Separation at 2050 rpm (mins)133 ± 5 40 ± 10

Example 7

Bloating Study: a bloating study was also conducted on gel basedabrasive containing compositions of the present invention to evaluatetheir chemical stability profiles. Unexpectedly, the gel based abrasivecontaining compositions of the present invention which comprise fromabout 9 to about 25%, by weight, propylene glycol; from about 14 toabout 32%, by weight, glycerin; and from about 1 to about 15%, byweight, of an additional linear and/or crosslinked polyvinylpyrrolidone,do not bloat to an unacceptable extent after 1 week of aging at 60° C.

The data described in the Examples evidences the unexpected improvementin chemical and physical stability demonstrated by compositions of thepresent invention.

While particular embodiments of the present invention have beenillustrated and described, it will be obvious to those skilled in theart that various changes and modifications may be made without departingfrom the spirit and scope of the invention. It is therefore intended tocover in the appended claims all such changes and modifications whichare within the scope of the invention.

1-19. (canceled)
 20. An oral care composition comprising: (i) awhitening complex comprising crosslinked polyvinylpyrrolidone complexedwith hydrogen peroxide; (ii) a humectant selected from propylene glycol,glycerin, and combinations thereof; and (iii) a calcium abrasive;wherein the oral care composition is substantially anhydrous.
 21. Anoral care composition comprising: (i) a whitening complex comprisingcrosslinked polyvinylpyrrolidone complexed with hydrogen peroxide; (ii)a humectant system comprising propylene glycol, glycerin, or acombinations thereof; (iii) a calcium abrasive; and (vi) from about 10to about 40 wt.%, based on the total weight of the oral carecomposition, of one or more polymers comprising an ethylene oxide,propylene oxide block co-polymer of average molecular weight greaterthan 5000 Da, wherein the ethylene oxide, propylene oxide blockco-polymer comprises (ethylene oxide)_(x)-(propylene oxide)_(y) whereinx is an integer of 80-150 and y is an integer 30-80.
 22. The oral carecomposition of claim 21, wherein the oral care composition issubstantially anhydrous.
 23. The oral care composition of claim 21further comprising an anticalculus agent selected from the groupconsisting of phosphates, polyphosphates, polyaminopropanesulfonic acid,hexametaphosphate salts, zinc citrate trihydrate, polypeptides,polyolefin sulfonates, polyolefin phosphate, diphosphonates, acombination of two or more thereof.
 24. The oral care composition ofclaim 21 further comprising one or more thickener selected from thegroup consisting of carbomers, carrageenans, cellulosic polymers, andnatural gums, wherein the thickeners are present in a total amount ofabout 5 to about 35 wt.%, based on the total weight of the oral carecomposition.
 25. The oral care composition of claim 24, wherein the oneor more thickener comprises hydroxyethyl cellulose, carboxymethylcellulose, xanthan gum, or a combination of two or more thereof.
 26. Theoral care composition of claim 21 further comprising a surfactantselected from sarcosinates, taurates, sodium lauryl sulfate, sodiumcocoyl monoglyceride sulfonate, sodium lauryl sarcosinate, sodium laurylisoethionate, sodium laureth carboxylate sodium dodecylbenzenesulfonate, cocoamidopropyl betaine, and a combination of two ormore thereof.
 27. The oral are composition of claim 21 furthercomprising a stannous ion source selected from stannous fluoride,stannous chloride dihydrate, stannous pyrophosphate, stannous formate,stannous acetate, stannous gluconate, stannous lactate, stannoustartrate, stannous oxalate, stannous malonate stannous citrate, stannousethylene glyoxide, and a combination of two or more thereof, wherein thestannous ion source is present in an amount of 0.1 to 7 wt.%, based onthe total weight of the oral care composition.
 28. The oral arecomposition of claim 21 further comprising a fluoride ion sourceselected from monofluorophosphate, a fluorosilicate salt, and acombination of two or more thereof.
 29. The oral care composition ofclaim 21, wherein the humectant system consists of one or more ofpropylene glycol, glycerin, and a combination thereof.
 30. An oral carecomposition comprising: (i) a whitening complex comprising crosslinkedpolyvinylpyrrolidone complexed with hydrogen peroxide; (ii) additionallinear polyvinyl pyrrolidone and/or cross-linked polyvinylpyrrolidone;(iii) a humectant; and (iii) a calcium abrasive, wherein the oral carecomposition is substantially anhydrous.
 31. The oral care composition ofclaim 30, wherein the humectant is present in an amount from 50 to 70wt.%, based on the total weight of the oral care composition.
 32. Theoral care composition of claim 30 further comprising an anticalculusagent selected from the group consisting of phosphates, polyphosphates,polyaminopropanesulfonic acid, hexametaphosphate salts, zinc citratetrihydrate, polypeptides, polyolefin sulfonates, polyolefin phosphate,diphosphonates, or a combination of two or more thereof.
 33. The oralcare composition of claim 30 further comprising one or more thickenerselected from the group consisting of carbomers, carrageenans,cellulosic polymers, and natural gums, wherein the thickeners arepresent in a total amount of about 5 to about 35 wt.%, based on thetotal weight of the oral care composition.
 34. The oral care compositionof claim 33, wherein the one or more thickener comprises hydroxyethylcellulose, carboxymethyl cellulose, xanthan gum, or a combination of twoor more thereof.
 35. The oral care composition of claim 30 furthercomprising a surfactant selected from sarcosinates, taurates, sodiumlauryl sulfate, sodium cocoyl monoglyceride sulfonate, sodium laurylsarcosinate, sodium lauryl isoethionate, sodium laureth carboxylate,sodium dodecyl benzenesulfonate, cocoamidopropyl betaine, and acombination of two or more thereof.
 36. The oral are composition ofclaim 21 further comprising a stannous ion source selected from stannousfluoride, stannous chloride dihydrate, stannous pyrophosphate, stannousformate, stannous acetate, stannous gluconate, stannous lactate,stannous tartrate, stannous oxalate, stannous malonate stannous citrate,stannous ethylene glyoxide, and a combination of two or more thereof,wherein the stannous ion source is present in an amount of 0.1 to 7wt.%, based on the total weight of the oral care composition.
 37. Theoral are composition of claim 30 further comprising a fluoride ionsource selected from monofluorophosphate, a fluorosilicate salt, and acombination of two or more thereof.
 38. The oral care composition ofclaim 30, further comprising a sweetener selected from saccharin;sucralose; and a combination thereof.
 39. The oral care composition ofclaim 30, further comprising one or more polymers comprising an ethyleneoxide, propylene oxide block co-polymer of average molecular weightgreater than 5000 Da, wherein the ethylene oxide, propylene oxide blockco-polymer comprises (ethylene oxide)_(x)-(propylene oxide)_(y) whereinx is an integer of 80-150 and y is an integer 30-80.